Non-clogging splitter unit for dividing the flow of fluid-conveyed material



June 1968 F. w. HOCHMUTH ETAL 3,387,895

NON-CLOGGING SPLITTER UNIT FOR DIVIDING THE FLOW OF FLUID-CONVEYEDMATERIAL 5 Sheets-Sheet 1 Filed Dec. 29, 1966 INVENTORS FRANK W HOCl/MUTH Jbse u F MUM-EN June 11, 1968 F. W. HOCHMUTH ETAL NON-CLOGGINGSPLITTER UNIT FOR DIVIDING THE FLOW OF FLUID-CONVEYED MATERIAL FiledDec. 29, 1966 FLOW DIV/PER K 5 Sheets-Sheet 2 3 Sheets-Sheet 3 HOCHMUTHETAL OF FLUID-CONVEYED MATERIAL June 11, 1968 NON-CLOGGING SPLITTER UNITFOR DIVIDING THE FLOW Filed Dec. 29, 1966 R QWQSR ZONM INVENTORS FRANK MHOC'IIMUI'H JOSEPH F- MULLEN United States Patent LOGGING SPLITTER UNIT1 0R DIVIDING IE FLOW 0F FLUID-CGNVEYED MATERIAL Frank W. Hochmnth, WestSimsbury, and Joseph F. M ullen, West Hartford, Conn, assignors toCombustion Engineering, Inc, Windsor, Conan, a corporation of elaware DFiled Dec. 29, 1966, Ser. No. 605,766

2 Claims. (Cl. 302-64) ABSTRACT 61* THE DISCLOSURE In a Y-type flowdivider for splitting a main stream of fluid-conveyed material flow intobranch streams, tne flow-splitting member at the apex juncture of thetwo branch conduits being made of plate stock which has small openingsin large number distributed thereover. Such splitting member is shapedwith a frontal portion that faces into the flow of the incoming mainstream; it has first and second side portions that extend downstreamfrom the frontal portion into flow-guiding relation with the branchconduits; and it is provided with means for establishing through theopenings a generally upstream flow of compressed medium in the form ofjets which create along the plate front and sides a boundary layer Whoseeffect is to prevent the material in the incoming main stream frombuilding up on the flow-splitter plate.

Summary of the invention Our invention relates to the pneumatic or otherfluid transport of fuels and other materials, and it has specialreference to an improved method of and apparatus for dividing a mainstream of such transported material into two or more branch streams.

Broadly stated, the object of our invention is to accomplish such flowdivision in an improved way which prevents the material fibers and otherparticles from depositing upon and adhering to the throat of the divding device and there accumulating with resultant restrlction orblockage of flow into and through the branch aths.

p A more specific object is to achieve the above through a novelinjection of compressed air or steam or other gas between theflow-divider throat and the material 1n the approaching main stream,which injection establishes and maintains a controllable boundary layerby which such main-stream material is kept from adhering to the throatmember.

Another object is to accomplish the foregoing by using a divider throatplate which contains a large number of free openings of small diameterand by passing the mentioned compressed medium through those plateopenings in directions which are generally counter to the mainstreamfiow and which produce jets having an energy content suflicient to keepthe material fibers and other particles from adhering to the throatplate, and the effect of which injection is to divert said materialalong the resulting low-friction boundary layer around the plate andinto the branch outlets of the divider.

Other objects and advantages will become apparent from the followingdescription of illustrative embodiments of the invention when taken inconjunction with the accompanying drawings.

Description of drawings FIG. 1 is a diagrammatic representation of oneform of fuel transport system wherein the flow-dividing improvements ofthe present invention are usable with practical advantage;

FIG. 2 shows one of the flow-dividing devices of FIG.

3,387,895 Patented June 11, 1968 1 to an enlarged scale and indicateshow that represented divider unit K can be organized and constructed inaccordance with a first embodiment of our invention;

and

FIG. 3 is a similar showing of our improved flow-dividing unit whenorganized in accordance with a second embodiment of the invention.

Description of preferred embodiments Our invention enables fuels andother materials to have their main flow streams divided into branchstreams without the hang-up and clogging difficulties encountered whenusing flow-dividing facilities of the prior art. Among the fuelmaterials whose flow division can be so benefited are those which thecopending Mullen application Ser. No. 594,040, filed Nov. 14, 1966,specifies as the bagasse resulting from cane-sugar production, wastewood products like tree bark and Wood chips and shavings, and industrialand municipal wastes. Non-fuel materials likewise can gain comparableflow-dividing benefits from a use of our invention in connectiontherewith.

The fuel transport system illustratively shown in FIG. 1

FIG. 1 indicates how our improved flow divider unit can be installed atthe two locations K in a system which is organized for the pneumatictransport of fuel from a source 18 at the drawing-view left to afuel-burning furnace 12 at the drawing-view right. Such fuel transportis effected through pneumatic lines 10 over distances from thefuel-supply location 18 to the furnace location 12 which range fromcomparatively short spans up to exceedingly long spans of thousands offeet or even of miles.

As the above-mentioned Mullen application Ser. No. 594,040 more fullybrings out, this FIG. 1 organization takes the fuel 18 from a conveyor14 whose chain 15 is continuously moving from left to right carriespockets of the fuel between slats 19 horizontally spaced along the chainlength. The fuel in these moving pockets 18 drops by gravity into thehoppers of fuel metering feeders 21. Rotating feeder drums equipped withblades then meter that fuel 18 at a predetermined rate into air locks 24and thence into the associated transport lines 10 at points downstreamof the air compressors 16 at the left or inlet ends of these lines.

Introduced by each compressor 16 behind or upstream of the fuel 18 soentering the associated line 10 is compressed transport air adequate formoving the air-fuel mixture through the entire length of the line andinto the associated nozzle A or B or C or D of the furnace 12. Thisprimary or transport air enters the lines 10 from the compressors 16 ata pressure ranging from about 2 pounds per square inch up to as high as50 pounds per square inch, depending upon the transport distance to bespanned. Each pound of such primary air serves to transport four or morepounds of the fuel 18 through its line 10 at the relatively high speedof from 50 to feet per second.

In arriving at the furnace or receiving end of the FIG. 1 system, thisfast-moving fuel enters the furnace 12 via the earlier-mentioned nozzlesshown at A-BC-D in the right portion of FIG. 1. As here represented,these nozzles direct their fuel-air streams tangent to an imaginaryfiring circle 13 within the furnace, thereby facilitating bothsuspension drying and suspension burning of the fuel in the advantageousway which the copending Mullen application Ser. No. 594,040 more fullyexplains.

How our non-clogging flow dividers K benefit the illustrative FIG. 1system The pneumatic transport organization of FIG. 1 just describedutilizes our improved flow divider unit at each of the two points markedK. At the upper of these two points the .fiow divider K is installed inthe right or delivery end of the transport line a where it serves todivide the main transport stream from that line between the two fuelnozzles 26 and 27 of furnace burner B. And at the lower of those twopoints a second fiow divider K similarly serves to split the main flowfrom transport line 10b between the two branch conduits 28 and 29respectively leading to furnace burners A and D. The main flow streamshere divided is illustratively shown as combining at line 10bs entranceend the flows from both of the two feeder-compressor units 21-2516 whichlead into the flow combiner designated 30 in FIG. 1.

This second or line 10b utilization of our improved divider K enablesthe single transport conduit 10!) to sup ply both of the furnace burnersA, and D with their needed fuel-air streams, with such two branchstreams being split at K from the main flow stream which the enteringend of that line 10b receives at 30 from the two feeder-compressor units21-25-16 mentioned immediately above. Those two fuel-air introducingunits can if desired be replaced by a single unit 21-2546 whose capacityis double that of each of those two. And the first or upper FIG. 1utilization of our non-clogging divider K similarly enables the twonozzles 2627 of furnace burner B to receive their fuel-air supplythrough the single transport line 10a of FIG. 1. In systems of this FIG.1 type involving transport distances of hundreds of feet or thousands offeet or even longer, such use of the single transport line 10a to supplyboth burner nozzles 26 and 27 and such use of the single pneumatic line10b to supply both of the furnace burners A and D opens the way forinstallation savings of such high order as to be economicallyattractive.

The invention embodiment which FIG. 2 hereof shows In the embodiment ofour invention represented in FIG. 2, the throat plate 32 at the junctureof the two branch conduits there designated 34 and 35 is provided withsmall openings 36 in large number distributed throughout the centerportion of the plate directly facing the main pneumatic conduit 10 andalso throughout the adjoining side portions which lead to the two branchpaths 34 and 35. Immediately downstream of the so-perforated throatplate or flow divider 32 is a transverse seal plate 37 which completelycovers the opening downstream of the throat plate and the periphery ofwhich is attached to the opening-defining members in a fluid-tightmanner as by welding. In this way there is produced a chamber 39 definedat its downstream side by plate 37 and whose upstream and lateral sidesare defined by the perforated throat plate or flow splitter member 32,here shown as being shaped in the form of a spherical head. Othershapings or profiles for this plate 32 can of course be substituted ifdesired.

An inlet conduit or pipe 38 leading through plate 37 into the so-formedchamber 39 serves to supply the chamber interior with air or steam orother gas at a pressure higher than that within transport line 10 at thepoint of its connection with divider K. For each installation suchchamber 39 pressure is chosen to be enough greater than the pressure ofthe main flow stream as to develop the energy required for establishingaround throat plate 32 the boundary layer earlier mentioned. In practicethis dilterential can be selected within the range of from 1 to 100pounds per square inch, depending upon system characteristics and thenature of the material being transported and divided.

For keeping such difierential pressure at or close to its selectedvalue, use may if desired be made of the control system shown in FIG. 2.There a controller 54 responsive to signals from taps 55 and S6 adjuststhe valve 57 in supply line 38 so as automatically to hold the pressurewithin chamber 39 at its said selected value above the line 10 pressureat the flow divider entrance.

Such compressed gaseous medium as so delivered into the divider chamber39 by pipe 38 may be derived from any suitable source. In theillustrative system of HG. 1 such source is represented in the form ofan air pump 42 driven by motor 41 and serving to keep an accumulatortank 43 filled with air at the particular pressure which the system flowdividers K require in order to prevent hang-up and clogging of the fuelor other material being passed therethrough.

Such air or steam or other gas under compression is led from tank 43 toeach divider inlet pipe 38 through the pressure-control valve 57 alreadymentioned. Asthe description proceeds, it will become evident that thisaccumulator tank 43 of FIG. 1 can if desired have the compressed airtherein replaced by some other gaseous medium such as steam from asuitable source not shown. Nitrogen or argon or other inert gas suitablycompressed likewise may be utilized in the FIG. 1 tank 43 in situationswhere the presence of oxygen or moisture in the fiow divider chambers 39may be undesirable.

How the flow divider of our invention prevents hang-up and clogging ofthe material being passed therethrouglr In operation of our improvedflow dividers K the fuel or other material delivered thereinto by theassociated transport line 10 is split in a uniquely advantageous way bythe throat plate or flow divider member 32 into the two branch streams34 and 35.This advantageous form of splitting is in sharp contrast todivider constructions of the prior art wherein the throat elementscorrespond ing to plate 32 of FIG. 2 is unperforated and thus functionsmerely as a simple mechanical splitter of theincoming main flow stream.When handling materials such as the fiber-containing bagasse and barkfuels as earlier mentioned as well as non-fuel materials, such prior-artflow dividers have typically been unsatisfactory in that the materialcoming into physical contact with the splitter element 32 between outletbranches 34 and 35 adheres to and builds up upon such element withresultant decrease in outflow through either or both of the branch pathsand eventual clogging of those paths.

Such troublesome and unsatisfactory operation is eliminated by theimproved flow dividers K of our present invention. The arrangement ofour FIG. 2 accomplishes this through the medium of the mentioned jets ofcompressed gas, whether it be air or steam or an inert medium, whichflow from the internal chamber 39 out through the throatplate openingsor perforations 36. These jets of com- I pressed gas so emanating fromthe central openings 36 directly oppose the main stream flow fromtransport line 10, while the companion jets so emanating from the sideperforations of throat plate 32 supplement the center ones by divertingthe material in the divided flows away from the plate sides inout-of-contact relationship therewith.

The higher pressure maintained within the divider chamber 39 issufliciently above the main-stream pressure at the divider entrance asto give the opening 36 jets an energy or potential force which is higherthan that of the material fibers and other particles that are advancingtoward or contacting the throat plate or flow splitter member 32. Thisresults in establishing upstream of the plate center and also along eachof the two plate sides the mentioned boundary layer of said compressedmedium.

Such layer minimizes physical contact by the main stream fibers orparticles with the flow splitter or throat plate 32, around which platethe material flow in such main stream divides into the two branchstreams 34 and 35. In the event some of the material fibers or particlesdo get through the boundary layer and lodge upon the flow splitter plate32, such lodging is only temporary because the high-energy jets fromperforations 36 therebeneath act physically to lift all of suchtemporarily lodged material away from plate 32s surface and back intoone or the other of the divided branch streams 34 and 35.

Further concerning the small openings 36 in the throat plate 32, it maybe desirable in some instances to have various sized openings indiffering areas of the plate in order to obtain an optimum effect of thejets upon the flow of conveyed material through the divider. Forexample, those openings 36 on the frontal portion of throat plate 32 canbe made larger than those long the plate sides with resultant greaterenergy in the front jets than in the side jets.

The foregoing functioning on the part of our FIG. 2 flow divider Kprevents the material passing therethrough from hanging up at the pointof division between outlet branches 34 35 and thereby eliminates theobjectionable clogging so characteristic of the comparable flow dividersof the prior art.

The invention embodiment represented in FIG. 3

The basic approach exemplified by FIG. 2 hereof is repeated by thesecond embodiment of our invention as illustrated in FIG. 3. Here as inFIG. 2 the main stream flow from transport line .18 separates aroundthroat plate 32, into the two branch streams of outflow conduits '34 and35. But instead of all of the compressed air or steam or inert mediumbeing continuously delivered through supply pipe 38 into the singleinternal chamber 39 of FIG. 2, the alternate organization of FIG. 3utilizes two separate chambers 39a and 3% which are divided one from theother by a longitudinal plate 46. And further incorporated into the FIG.3 design is additional provision for subjecting each of these twochambers 39a and 39b to short periods of internal pressure supply whichare separated by intervening periods of supply pressure cut-off.

-In accomplishing the latter, we interpose a valving unit '48 betweenthe main pressure supply pipe 38 and the two branch supply pipes 38a and38b respectively leading to chambers 39a and 39b. Utilized by this unit48 is a stationary ring member 5t) into which the branch supply pipes3811-3812 lead at points circumferentially spaced one from the other asshown. Inside of this stationary ring 5%) there is installed aspoke-like structure 51 which is slowly rotated (via suitable drivemeans not shown), as at from 1 to 5 rpm. The compressed medium needed toaccomplish non-clogging operation of the flow divider is conveyed bysupply pipe 33 into the center of this rotating member 51, and the fourrepresented spoke elements of that member 51 are in direct communicationwith such delivery end of that pip-e 33.

With this valving element 51 in the position shown by FIG. 3, thecompressed medium supplied from pipe 38 flows through the spoke elementin register with branch pipe 38a and then on through that branch pipeand into the chamber half 39a. Under this condition the other chamberhalf 3% is not connected with the main supply pipe 38 and thus isunpressurized. Rotation of the valving element 51 in the counterclockwise direction of the arrows brings the spoke element previously inregister with 38a into a new position of register with branch pipe 38band thereby transfers the supply of pressurized medium from the firstchamber half 3% to the second chamber half 3%.

Continued rotation of valving element 51 at the appropriate slow speedearlier referred to has the effect of communicating thecompressed-medium supply from pipe 38 alternately to first the chamberhalf 3941 and then the chamber half 39b and then back to 39a and so on,with the transfer cycle repeating itself at a frequency which depend-supon the speed at which valving element "51 is driven. Such speedpreferably is selected to result in several cycles per minute of theabove pressure application 6 and shut-off as applied to each of thechamber halves 39a and 39b.

The operating advantages of our FIG. 3 embodiment are basically similarto those earlier described with reference to the first or FIG. 2embodiment. But instead of the entire single chamber 39 being subjectedto internal pressure all the time on a continuous basis, the extendeddesign of FIG. 3 repeatedly switches the application of such internalpressure between the two chamber halves 39a and 3%. In consequence, thetwo perforated plate halves 32a and 32b alternately function to dislodgefrom their respective surfaces any fibers or particles of the materialwhich the FIG. 3 flow divider receives from transport line 10 and Splitsinto the two separate flow paths 35 and 36. In certain situations andwhen handling certain materials such a pulsing action is found to beadvantageous.

While we have shown and described two preferred embodiments of ourinvention, it is to be understood that the inventive improvements hereindisclosed are not limited to those illustrative embodiments but may beotherwise variously embodied and practiced within the scope of thefollowing claims.

What we claim is:

1. In a Y-type flow divider having an inlet conduit adapted to receive amain flow stream of fluid-conveyed material and having first and secondbranch conduits adapted to convey divided streams of said main flowmaterial out of the divider from the inlet conduit interior, thecombination of a flow divider of a Y-shaped configuration having aflow-splitting member disposed between the branch conduits at their apexjuncture inside the divider body and formed from curved plate stockwhich has small openings in large number distributed substantially overthe entire plate area and which is shaped to provide a frontal portionthat faces into the how of said incoming main stream together with firstand second side portions that extend downstream from said frontalportion into flow-guiding relation with the interiors of said first andsecond branch conduits, and means for establishing through the openingsin the splitter plate and from the plates downstream side a generallyupstream flow of compressed medium in the form of a large number of jetswhich create a boundary layer of said jetting medium over the entireplate area of said flow splitting member whose affect is to prevent thematerial in said incoming main stream from collecting and building up onthe flowsplitter plate during operation of the divider.

2. A flow divider organized as defined by claim :1 wherein the said jetsof ocmpressed medium issuing from the splitter plates said frontalportion do so in upstream directions which are opposite to thedownstream fi-ow of the material in said incoming main stream, andfurther wherein the companion jets of said compressed medium issuingfrom said plates two side portions do so in a gen eral sidewiserelationship to the flow directions taken by said divided branch streamsduring their passage along those plate side portions on their way intothe dividers said branch conduits.

References Cited UNITED STATES PATENTS 3,149,885 9/1964 Walsh; 302-64RICHARD E. AEGERTER, Primary Examiner.

EVON C. BIJUNK, ANDRES H. NIELSEN, Examiners.

M. L. AJEMAN, Assistant Examiner.

